1933-04-13 — Page 2

Marine Wireless Activities During 1932

PROGRESS IN DESIGN AND

ORGANISATION

Although, 1932 was a year of continued anxiety in commer.

·cial affairs, every opportunity was taken by the Marconi Com- pany to press forward with wireless developments, with the result that the year was one of great activity and considerable pr gress in wireless. The outstanding feature of the year's develop. ment we the extension which took place in the use of wireless telephony in constal vessels and trawlers, and the provision of wireless telephone installations at a number of Post Office Const Stations for communication with ships. In addition to this, however, much progress was made, in increasing the efficiency of wireless apparatus and in simplifying the operation of wireless sets. The year'. development is reviewed in the following article.

HONG KONG DAILY PRESS, THURSDAY, APRIL 13, 1933,

Communication between Cosat stations and ships using these low! power installations is carried out on the simplex principle, that is to say the receiver is out of opera tion while the subscriber is speak ing and when he has finished the transmitter conses to operate and the receiver comes into circuit with the telephone-a system with which wo were familiar in the early type of land telephone which had a spring in the handle which had to

be depressed when the subscriber

Was speaking. The same principle is adopted in the simplex wireless telephone instrument, the change over from "send" to "receive" be ing carried out, by means of a re lay operated from a pressed switch in the hand microphone handle.

Large Ship Telephony.

Short Wave Apparátus, Apparatus has been designed for short wava telegraph requirements. where the power available on the ship is not great and where the accommodation is limited. The transmitter of this installation has able from 15-40 metres, and the A wave range continuously vari design is such that the setting on drift during message of 100 words a particular frequency and is in accordance, with the C.O.I.R. recommendations. Tests with these sets show that it has been possible to keep up good communication ne tween English and Australian waters although the output from the generators only a half kilo- watt.

the

Attention has also been given to the design of short wave receivers und improvements introduced into} existing sets.

On the larger ships which can carry more elaborate, installations --such as the "Homerie," "Em- press of Britain," the "Monarch. of Bermuda" and the "Queen of mand has arisen for a more highly In the past few months a de- Bermida"-duplex telephony, that is the type of apparatus with efficient form of short wave recei which the Nistener un interrupt 10-100 metres to meet special re- ver covering a wave band of from the speaker at any time and therequirements and a suitable set has is no need to press a switch in the bean designed which is remarkable iver handle, is provided, and for its simplicity of operation, the it is possible to put a subscriber tuning adjustments being as easy straight through from the ship to the home of any telephone subscri her on land.

Direction Finding.

as on medium wavelengths,

Public Address System.

There is an increasing demand

THE value of wireless both from, munication with small power wire the point of view of convenien less telephone sets on board ship, ce and of safety has been increas- these stations being at Wick, Fist

Demands have also arisen and ingly recognised during recent guard, and the Humber. In May,

have been met for receivers work. years by owners and masters of the 1939, however, the General Post The technique of this duplexing directly off mains supplies ot smaller classes of ships that are Office having regard to develop telephony apparatus for large. not required by law to carry wirements to which reference has al ships has been considerably devs 10 or 220 volta D.C. This has in- less installations. Broadcasting is ready been made, intimated that loped during the year, and reli volved the design of high tension undoubtedly having its effect on it was prepared to equip, further able and efficient services are avail. and low tension eliminators for the seaman's outlook. When ashore, wireless telephone coast stations in able for voyagers on all ships ft use on D.C. mains and the intro- duction of indirectly heated Cat- he is familiar with the conveni- order to test the commercial possited with Marconi marine installa hode valves. Designs have alsa ence and simplicity of wireless bility of auch a service for ships tions of this type.

been evolved for working these re communication, with the result in home waters; and the Marconi

ceivers off A.C. 50 volt machines. that sea voyages during which the Marine Company was entrusted ship is cut off from all communi with the task of fitting eight more cation with the shore, do not seem coast stations with 300 watt wire- to be in keeping with modern con- less installations for this purpose, ditions of life. A growing desire thus making a complete chain of on the part of seamen serving in eleven stations round the coasts of all classes of ships to be in touch the British Isles. with the shore when at therefore only to be expected,

The commercial value to owners of being able to communicate with their vessels at any time is also being increasingly recognised, and, indeed, is almost essential in the conditions of commercial lift to day. From the point of view of the safety of their ships and ear go, there is also much to be said in favour of wireless when, as Mr. W. A. Bouter has pointed out, the percentage of total loss of British vessels has decreased from. 1.24 in 1909 to .48 per cent. in 1931.

Wireless Telephony:

159

B The equipment of these stations was begun immediately, and they were completed on September 11th. Later, when some experience of the work of these stations had been obtained, the Post Office requested the Marconi Company to relit the Humber Station with apparatus similar to that installed in the other stations, and this work was completed in November.

Coast Stations.

the

Direction finding systems, which are improved in sensitivity and reż liability each year, have been the subject of further useful research while the number of Marconi auto matic wireless beacons has been in creased by three, new stations com pleted during the year on Uruguayan coast. Two more Mar. coni beacons for Chinese waters, in addition to that installed in 1630 at North Saddle Island (near Shanghai), have been ordered for, Shaweishan Island, near the mouth of the Yang-taze-Kiang, and Gutz taff, also on the important - ship- ping routes to Shanghai and the Yang-tse-Kiang. The equipment

for these stations will be specially designed and constructed for use under tropical conditions.

1

for Public Address Systems an with band repeaters and the latest board ship. These are linked up model of band repeater equipment for big ships is so designed as to Permit of the same amplifier beins, used for either wireless, gramo phone or public address microphone imput, all of which can run simultaneously. It is also arrang ed that any one, of these three im- puts can be delivered to any on

of

number of lond-speakers situated in various parts of the ship.

A further development has been

By the and of the year there were

the provision of Public Addres some 160 ships, mostly coasting

Systems designed to work off either vessels and trawlers, equipped with

D.C. or A.C. supplies. In the W. Transmission, Marconi wireless telephona sets

"Empress of Britain," in which and able to work with these sta

the first Marconi Public Address Considerable research work has System was fitted, loud-speakers Fully alive to these modern tentions. Beginning with Wick in the

on C.W. and were placed in the Dining Balbon dencies, the Marconi Marine Com. North of Scotland and coming been carried out munication Company Limited has down the East Coast, there are 1.C.W. transmitters during the and by this means speeches could year. The designs of these trans- be amplified po as to be perfectly given special attention in recons stations at Cullercoate, the Hum years to the design of small and ber and North Foreland. Then, mitters have been carefully exaudible in any part of the room. compact wireless telephone instal along the South Coast there are amined to ensure that all their

From the above summary of the lations which are sufficiently sim- Niton in the Isle of Wight, and operating wavelengths come with ple in control, to be operated by Land's End; with Fishguard, Sea- in the standards recommended by activities of the past year, it will personnel unskilled in electrical forth, and Port Patrick on the the International Technical Con- be seen that every effort has been

for Radiol matters. A design of apparatus West Coast, and Malin Head and sultative Committee has been evolved which can be Valentia in the Irish Free State. Electric Communications (C.C.I made to improve the service wire- operated without trouble by the By means of these stations all ships t.) and manipulation has bean, so less can render to the British Mer- and arranged that for any given wave chant Navy and to provide facili

lengths these transmitters comply officers of a cargo ship or by the voyaging in British waters

ships on international voyages skippers of trawlers and other while within 200 or 300 miles of with the accuracy of Betting Teties for dealing with increased. business when batter times return. small craft.

The design of this the British coasts can, if suitably commended by this Committee.

equipped, communicate by tele- set is extremely robust and its phony with one or other of these operation is go simple that the coast stations, the service area of whole manipulation of tuning each station having been arrangel to overlap that of the next adjoin- carried out by a single knob con

ing station on either side, so as to troj.

form a 'complete service arca round the British Isles.

Until the middle of 1932 thers were only three British wireless coast stations equipped for com-

LAST FE WDAYS

SALE OF

BRUNSWICK

RECORDS

In order to meet the service re- quirements of the shore station, the Marconi Marine Company de- signed a special telephony/tele- graphy transmitter to work off the station mains with power to the anodes of 300 watts. The receivers were also designed to work wher necessary off the station mains.

Remarkable results beth on 1.C. W and Telephony have been ob tained between these stations and the small telephony sets installed on board ship. The average day- light telephone range of these sto- tions is about 150-200 miles, the lower ranges being in the congest- éd aread of the South Coast_and- higher ranges being obtained in other areas. At night actual tele. phone communication has been es tablished and maintained between Valentia and the White Sea, a diz- tance of nearly 4,000 miles. Such

HAVE YOU HEARD THESE?

Here are lists of long-wave and short-wave stations which should be picked up by anyone in Hong Kong who has s mode rately good et suitable for re- ceiving such signals, Success in plcking up these stations also depends very largely upon fav ourable atmospheric conditions. Readers are invited to add to this list should they succeed in picking up any station not in- cluded in either of these lists.

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Gall Sign K.Z.I.B. 1,163 K.B.MS. 1.093

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345 Tokyo JO.A.E 870 383 Hiroshima J.O.F.K. 850 336 Hong Kong -Z.B.W.-.

848 V.U.B. 357.1 Bombay

840 361 Sapporo JOLE. 830 J.O.D.K. 820 J.0.0.K. 370 Nagoya

810 370.4 Calcutta." V.U.C. 809.0

790 770

386 Keijo

380 Kumamoto J.O.G.K. 390 Bendzi J.O.E.K. 395 Dairen... J.Q.A.K. 760 400 Osaka J.O.B.K. 750 CMPB. 739 K.Z.R.M. 625

410 Canton 480 Manila

SHORT-WAVE STATIONS.

STATION

CALL SIGN:

KILO

WAVE

RECEPTION.

4

TIME (HONG KONG)

OF WORKING

SETS

a range is, of course, unusual, but

Frequently night ranges of 1,000 | miles have been achieved.

$7,86

60.12 56.7

Dobints(Germany) A.F.K Khabarovsk (Euria) E.4.97. Naushy Mosco Rome Perth

4,434 Mon, Wed. &, Fri., 6 p.m. & 2 a.m

A.G.J.

4,090 6-10 pas. -5,291 Not regular

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Telephone 24848.

These coast stations work on wavelengths between 100-200 metres 48.

and the aorial system is usually »

6,000 Tues., Thurs., Sat., 8p.m.

6,896 Bunday midnight"

9,090

7,143 Daily 6,80

V8.1.A.B. 7310 Not regular

Bingapore single wire about 100 ft. Tong, -$9,8 Kootwijk (Holland) P.C.L.

Wavelengths

87. Bangkok (Blam)

86.2 Sydney '81,55 Melbourne 21.48

Schenectady

The Marconi ship installation 18 81.20 normally supplied as a telephone 81.88

81.

operating on WV 285 Jengths between 100 and 220 metres,

37.8 on also be supplied

telegraph

but telor

HS4PJ.

3.B.L

p.m. & 11 p.m.

15200 Daily 11.p.m 8,103 Tues, & Fri, 9 p.m.-1 a.m. 9.280 Not regular 9,608 Not regular 9,530 Dally.

Lo 9.508 Net

W.9.X.A.F.

(Holland) P.C.J.

9.620 Fr. 3 am, Sat. 8 am, & 10 a.m. 9,590 Not regular

9,677 Midnight d

(Kenya)

7.LO.

t daily

Sydney Bandoeng

2.M.E.

10,626 Not alar

P.LB.

75.88 Chelmsford (Engistad) 6.9.W.

11,020 Midnight 8 am. daily 11,752 7.80 5 pin, & 8 am, dally, except

Saturday and Sunday

working. PNG

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Schenectady"

both on telephony and LCW tele graphy over these wavelengths, while sby the pädition

ther unit, it can be made

rate on 109 290 metres and 800

500

RAY

mètres telephony

telegraphy

to -operate off a 19-volt?

K.1.X.E.

12,240 Nightly V.2.1.0. | 19,850 || 4 mm. Wod, Fri, Sat,

16,102 Dally 6.80 p.m. to midnight 16,804 Daily7 p.m. PATATES 17,280 | Daily 8 p.m.to

Kafternoon.

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